Pipe-threading tool.



B. BURDEN.

PIPE THREADING TOOL.

APPLICATION FILED 2312.11.1911.

gwve/wtoz MOT/VIC" Patented Dec. 31, 1912.

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UNITED STATES PATENT OFFICE.

BRADFORD BORDEN, 0F TORONTO, ONTARIO, CANADA, ASSIGNOR TO THE BORDEN COMPANY, OF WARREN, OHIO, A CORPORATION OF OHIO.

PIPE-THREADING TOOL.

To all whom it may concern:

Be it known that I, BRADFORD Bonnnn, of Toronto, in the Province of Ontario, Dominion of Canada, have invented certain new and useful Improvements in Pipe-Threading Tools; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

In some classes of die stocks or pipe threading tools at the completion of the threading operation the chasers, owing to the sudden cessation of resistance, open outwardly so quickly that the operators are frequently struck by one of the operating handles.

The primary object of this invention is to provide simple and highly efficient means which, while allowing the chasers to open automatically after the cutting operation is completed, will control and render gradual such opening movement.

A further object is to insure the automatic reengagement between the chaser-engaging plates and the controlling post after the chasers have opened outwardly at the end of a cutting operation. And a further object is to adapt the present invention to a tool capable of cutting pipes of different sizes at correct pitch and with threads of proper lengths.

The invention will be hereinafter fully set forth and particularly pointed out in the claims.

In the accompanying drawings, Figure 1 is an end elevation. Fig. 2 is a side View. Fig. 3 is a fragmentary view of the cam plate. Fig. 4 is a View thereof with parts broken away. Fig. 5 shows the cam plate with a single lug. Fig. 6 is a view of the post.

Referring to the drawings, 1 designates the chaser-carrier or housing; 2 the radially movable chasers mounted in guideways of the carrier; 3 lugs projecting from the chasers; 4 the cam or chaser-engaging plate having eccentrically-arranged grooves for taking in the chaser lugs; and 5 a post between which and the chasencarrier there is a relative longitudinal movement during the rotation of the carrier. In the present instance this relative movement is shown as being obtained by means of a stOp 6 with which the end of the pipe is designed Specification of Letters Patent.

Application filed February 11, 1911.

Patented Dec. 31, 1912.

Serial No. 607,946.

to engage, such stop being carried by a cross bar 7 extended perpendicularly to the axis of the tool and to which at one end is secured the post 5, a corresponding post 8 being secured to the other end of the cross bar. These two posts are shown as extended through sockets of an adjuster 10 which is adjustably secured to the chaser-carrier or housing as contemplated by my pending application for patent Serial No. 584,736, filed September 30th, 1910, the sockets of said adjuster extending through arcual slots 12 of the chaser-carrier, which latter is provided with the ordinary sockets 13 for the reception of the manipulating handles. But so far as concerns the subject matter of the present invention, it is immaterial what means are employed for securing the relative movement between the chaser-carrier and the post which controls the cam plate, which latter, as is well known in the art, while rotating with the chaser-carrier has a movement independently thereof for allowing or causing the chasers to uniformly recede during the threading operation. In the particular instance, the means shown for controlling the independent rotation of the cam plate consists of a diagonally-arranged lug 15 on the inner face of post 5, such lug entering any one of a plurality of cut-outs, or a signal cut-out, in the cam plate. According to the particular means shown the adjustment of the chasers to pipes of different sizes is obtained by releasing the adjuster from the chaser-carrier, and turning it axially, together with the posts, and the cam plate. The means shown for looking the adjuster to the chaser-carrier consists of a handled screw rod 16 projected through threaded openings in parallel ears of a split ring of the adjuster.

My present invention contemplates providing the cam plate with a fixed lug or other element adjacent to each cut-out in the periphery of the cam plate, and the wall of the lug is given a greater slant than the adjacent wall of the cut-out of which it forms a continuation, so that after the chasers cease their cutting operation their disengagement from the pipe will be gradual, thereby avoiding the sudden cessation of resistance. In other words, adjacent to a peripheral cutout 20 I provide the cam-plate with a lug 21 the face 22 of which is inclined or slightly curved, forming thereby a continuation of one of the walls of the cut-out. The threading operation is completed when the inner end of the diagonally arranged lug of the post passes from between the parallel walls of the cut-out, and in the further revolution of the tool, the cam plate, acting under the pressure of the pipe on the chasers, will be permitted to revolve independently of the chaser-carrier at an accelerated speed, thereby enabling the chasers to gradually open outwardly, the opening movement being controlled by the engagement of the inclined or curved face of the lug of the cam plate with the lug of the post. The rotation of the cam plate relatively to the carrier during the threading operation may be caused wholly by the interlocking engagement of the cam plate with the lug of the post, or it may be caused by the outward pressure of the pipe acting on the chasers, the rotation being controlled by the post. But in either event, after the threading operation is completed, the pressure of the pipe on the chasers will give to the cam plate an accelerated movement relatively to the carrier, and this movement is controlled and rendered gradual by the lug on the post.

To adapt a die stock for cutting threads on pipes of different sizes, and in order to obtain the correct length for the difl'erent thread pitches, I preferably form the cam plate with a plurality of peripheral cutouts, a lug being located adjacent to each cut-out. In Figs. 1, 3 and 4-, I have shown three cut-outs, with a controlling lug adjacent two of them, the lugs being of different lengths. In Fig. 5 I have shown a single cut-out with a single adjacent lug.

From what has been said it will be understood that as the threading operation progresses the rotation of the cam plate independently of its rotation with the chasercarrier is controlled by the diagonally-arranged lug of the post between which and the carrier there is a relative longitudinal movement, and that after the threading operation is completed the pressure of the pipe on the chasers will rotate the cam plate, and this rotation while at a greater speed than the rotation of the plate relatively to the carrier during the threading operation is controlled and effects the gradual outward opening of the chasers.

In each of the posts 5 and 8 I have shown screws having milled heads 25 which act as stops upon engaging the rear face of the adjuster, and thereby limit the longitudinal travel between the posts and the chaser-carrier. These stops prevent the lug of the post moving beyond the plane of the adjacent lug of the cam plate, so that when it is desired to reposition the parts for a second operation, it is only necessary for the operator to bear inwardly on the cross bar, and the engagement of the lug of the post with the posts may be withdrawn from the adjuster,

or outwardly sufiiciently far to enable the lug of the post to clear the lug of the cam late.

p Although I have shown and described the preferred manner of carrying out my invention, it will be understood that changes may be made in the construction and arrangement of parts without departing from the spirit of the invention.

I claim as my invention 1. In a pipe threading tool, the combination with a rotatable and longitudinally movable chaser-carrier, and a series of radially-arranged chasers, of a chaser engaging plate rotatable with, and also relatively to, the chaser carrier, said plate having an inclined surface of varying inclinations, and a post between which and said carrier there is a relative longitudinal movement, said post having a diagonally-arranged lug for engaging said inclined surface of the chaser engaging plate for controlling the independent rotation thereof during the threading operation and with which, at the completion of the threading operation, the greater inclination of said surface will engage to allow said plate to be turned at an accelerated speed by the pressure of the pipe on the chasers.

2. In a pipe threading tool, the combination with a rotatable and longitudinally movable chaser-carrier, and a series of radially-arranged chasers, of a chaser engaging plate rotatable with, and also relatively to, the chaser-carrier, said plate having in its periphery a diagonally-arranged cut-out and a lug having a surface forming a continuat1on on a greater inclination of one of the walls of said cutout, and a post between which and said carrier there is a relative longitudinal movement, said post having a diagonally-arranged lug for engaging said cutout for controlling the independent r0- tation of said plate during the threading operation and with which the inclined face of said lug will engage, after the completion of the threading operation, for controlling the movement of said plate under the pressure of the pipe on the chasers.

3. In a pipe threading tool, the combination with a rotatable and longitudinally movable chaser-carrier, and a series of radially-arranged chasers, of a chaser engaging plate rotatable with, and also relatively to, the chaser-carrier, said plate having in its periphery a plurality of cut-outs and a plurality of lugs of graduated lengths adj acent to said cut-outs, each lug being inclined in continuation of, but on a greater pitch than, one of the walls of the adjacent cut-out, and a post between which and said chaser-carrier there is a relative longitudinal movement, said post having a diagonally-arranged lug for entering any one of said cutouts for controlling the independent rotation of the cam plate during the threading operation and with which the lug of the cam plate adjacent the respective cut-out will engage, at the completion of the threading operation, for controlling the movement of said plate under the pressure of the pipe on the chasers.

4. In a pipe threading tool, the combination with a rotatable and longitudinally movable chaser-carrier, and a series of radially arranged chasers, of a chaser-engaging plate rotatable with, and also relatively to, the chaser-carrier, said plate having an inclined surface of varying inclinations, a post between which and said carrier there is a relative longitudinal movement, said post having a diagonally arranged lug for engaging said inclined surface of the chaserengaging plate for controlling the independent rotation thereof during the threading operation and with which, at the completion of the threading operation, the greater inclination of said surface will engage, and an adjustable stop carried by the post for permitting it to be moved to enable its lug to be cleared by the inclined surface of the plate.

In testimony whereof, I have signed this specification in the presence of two subscribing witnesses.

BRADFORD BORDEN. Witnesses D. S. TOVELL, H. M. GI-mIsTMAN.

Gopies at this patent may be obtained for five cents each, by addressing the "Commissioner of Patents, Washington, D. C. 

